Why can't you trust Vodacom's word

It's been 2 weeks since I asked for confirmation that my contract has been cancelled. I was told by Siyathemba that her team leader will do it and call me back to confirm in 48 working Hours. To date NOTHING!!! I will personally take the matter to the OBS should they even attempt to debit me on my next bill and the call recording will be proof of what I said and what I was told will happen. I even wrote to their customer services and they still haven'trep****. It's only when u ***** their services publicly do they even blink at the matter!!!!